1. Field of the Invention
The present invention relates to an ink-jet type printer and a function retrieval suction device for use in the same.
2. Description of the Prior Art
There is known an ink-jet type printer in which an ink is supplied from a detachable ink vessel to recording head nozzles. In such a printer, it becomes impossible to continue any printing if the ink vessel is not mounted in the printer since the ink is not supplied to the nozzles. The nozzles used in the ink-jet printer are of an extremely small diameter. If the nozzles are not used for a long time, the ink may dry or cause itself to create bubbles so that the ink will not be discharged from the nozzles. In order to overcome this, the ink-jet type printer is generally provided with a function retrieval suction device.
This device includes a cap which is mounted over the tip of a nozzle head and adapted to connect with a source of negative pressure through a flexible tube. Immediately before use, the cap is connected to the source of negative pressure to suck the ink from the nozzles so that the interior of the nozzles will be cleared to restore its proper function. The sucked ink is pumped to and collected in a waste ink tank which is mounted in the printer.
In a printer having such a structure, the waste ink tank is often formed integrally with an exchangeable ink cassette. When the ink cassette is replaced by a new ink cassette, therefore, the waste ink tank may also be discarded.
If the ink is drawn out of the nozzles under suction when the ink cassette provided with the waste ink tank is not mounted in the printer, the sucked ink is scattered in the interior of the printer to make the internal components thereof and recording papers dirty.
Where the waste ink tank is separated from the ink supply tank, there may be such a state that the waste ink tank is properly set in the printer while the ink supply tank is not mounted therein. In such a state, the ink will not be discharged from the nozzles since air is drawn into the nozzles without supply of ink if the suction is provided for the purpose of restoring the function of the nozzles.